BGE python: get list of vertices
While not blender specific, it is a basic python list operation. Start by creating an empty list, then append each item.

verts = []
for mesh in object.meshes:
    for m_index in range(len(mesh.materials)):
        for v_index in range(mesh.getVertexArrayLength(m_index)):
            verts.append(mesh.getVertex(m_index, v_index))


You may also want to adjust them as you go instead of making a list.

posadjust = [0,1,2,3]
negadjust = [4,5,6,7]
for mesh in object.meshes:
    for m_index in range(len(mesh.materials)):
        for v_index in range(mesh.getVertexArrayLength(m_index)):
            if v_index in posadjust:
                vertex = mesh.getVertex(m_index, v_index)
                vertex.x += 0.2
            elif v_index in negadjust:
                vertex = mesh.getVertex(m_index, v_index)
                vertex.x -= 0.2